Now you see me, now you don’t – True tales of sharks, bugs and other creatures hiding in plain view

Deep in the ocean, sharks pursue their prey. Large species found in open-water, like the famous Great White (Carcharodon carcharias) use their strength and speed to overpower prey, much like a lion on the savanna.

A school of fish (Photo credit: https://www.huffingtonpost.com/2013/09/18/fish-schools-genes_n_3947303.html).A musk ox herd in a defensive position (Photo credit: https://www.canadiannaturephotographer.com/waynelynch4.html).

And still others hide in their homes…

Baby rabbits hiding out in their burrow (Photo credit: https://www.pinterest.com/xracerxx/bunnies/).

Or even in plain sight.

A frog (Platypelis grandis) blends in with the moss in Madagascar (Photo credit: https://www.instantshift.com/2013/02/26/50-perfect-animal-camouflage-photography/).

The ocean is full of amazing examples of camouflage. Many fish blend into the background of their habitat to avoid being detected. Scientists call this crypsis. Crypsis is a great defense because if a predator cannot see or sense their prey they will not attack.

It also is an advantageous for predators, allowing them to hide from their prey until they are ready to ambush them. Many camouflaged ocean dwelling animals are both predators to smaller animals and prey to larger animals. Such ambush methods are commonly used by small sharks, like the spotted wobbegong shark (Orectolobus maculatus).

Found in deep waters of the Atlantic Ocean, the velvet belly, like other lantern sharks is bioluminescent (much like fireflies). It can illuminate its belly which may seem counterproductive for something trying to blend in. But blending in doesn’t just depend on the specific environment the organism is found in, it also depends on its predators. And predators of the velvet belly lantern shark include other larger sharks that have eyes on the top of their heads. These predators can detect fish or other prey above them by looking for shadows cast when the sunlight, shining down through the ocean surface, is blocked by the body of the prey organism. This is where having a bioluminescent abdomen helps the small lantern shark blend in. Instead of casting a shadow, the velvet belly produces its own light, mimicking the sunlight filtering down and making it nearly invisible from below. And their dark backs make them blend in from above as well! Check out this video.

Camouflage is not just crypsis, but also includes mimicry which is when organisms avoid detection by disguising themselves as another organism or object. For example, some seahorses pretend to be coral.

This pygmy seahorse (Hippocampus denise) is the smallest in the world and looks just like the coral in which it lives (Photo credit: https://mudfooted.com/world-smallest-seahorse-hippocampus-denise-pygmy-seahorse/).

As does the frogfish.

A frogfish (Antennarius spp.) hides in coral both as predator and prey (Photo credit: https://www.distractify.com/beautiful-diversity-of-coral-reefs-1197777333.html).

Whereas camouflage often requires animals to remain very still, mimicry works best if the animal can move like the organism they are copying. For example, the leafy sea dragon (Phycodurus eques) doesn’t just look like the kelp in which it lives, it also sways like kelp in the ocean current (see this video).

These animals are clearly well adapted to their specific habitats, as their patterns and markings might be quite obvious against a different background. However, some animals, like cuttlefish and the closely related octopii, can blend in across multiple habitats by literally changing their skin colors and patterns as they swim. Check out this amazing video and the NOVA documentary on cuttlefish.

However, when they open their wings it is a bright blue. So as they fly the contrast between bright and dull colors makes it seem like they are appearing and disappearing, making them hard to follow (see this video or this one about how the blue color is formed).

The blue morpho butterfly with wings open (Photo credit: https://www.rainforest-alliance.org/kids/species-profiles/blue-butterfly).

Mimicry is also common across many ecosystems. It is an effective defense because even if the animal can plainly be seen, it is not recognized as food. A bird looking for insect prey will not pay attention to this dead leaf…

What appears to be a dead leaf is actually the Indian leaf butterfly (Photo credit: https://mybutterflycollection.com/2013/05/25/indian-leaf-butterfly-or-orange-oakleaf-kallima-inachus-siamensis/).

Another example is this leaf insect which has one dark shade of green on top and a lighter shade below to mimic the leaves within which it lives. Its shape and markings make it look like a leaf that has been partially eaten. And it even goes so far as move like a leaf (see this video).

Disruption is another form of crypsis and it describes the use of color patterns like stripes or spots that break up the outline of the body, making it look less like an animal and more like light reflecting off of surfaces. Disruption makes it harder for the predator to both see and more difficult to attack if seen.

A good example is the American bittern, a wetland bird…

The American bittern (Photo credit: https://www.birdinginformation.com/birds/herons-bitterns-egrets/american-bittern/).

No matter what ecosystem you live near, you don’t have to go far to find examples of camouflage, in fact you can find them in your own backyard or neighborhood park, if you are observant, patient, and maybe a little bit lucky.

This past week some of my colleagues and I have been working with the curious and intelligent young scholar-scientists of Rutgers-Newark’s Aim High Academy. These rising high school seniors are working side-by-side with us to discover and document urban and suburban biodiversity in the wilds of New Jersey. In fact it was their discoveries that gave me the idea to write this week’s blog on mimicry and crypsis.

Like many of us going about our everyday life, my students were surprised to find so many insects and other living things right at our feet in our lawns…

… which also use camouflage but to catch prey rather than avoid predation. Mantids lie in wait for their prey, mimicking the plants they live in (see this video).

An orchid mantis from the tropics (Photo credit: https://www.imagekb.com/orchid-mantis).

We also found some insects that are purposely not blending in, like the monarch butterfly which uses warning coloration to scare off predators. Such advertisements will be the topic of my next post, so please check back soon.